Wonder if this would hold.......

I actually did this with some of the d-lux wefts in my last install.......not the exact same thing but close.  I needed to add some lowlights to the light blond so I stuck some loose hair to the wefts with liquid gold and then heated them flat with a straightening iron.  They held up really good and the lowlights actually survived the takedown with acetone (they were connected about 1/4 inch below the area I used the acetone although I'm sure some got on them).